A study of strain and sex susceptibility to colon carcinogenesis using 1,2-dimethylhydrazine (DMH) and azoxymethane (AOM) in mice and rats. Female rats were resistant to DMH carcinogenesis but not AOM, developing both colon and kidney tumors with AOM. Piperazine, a pinworm eradicator, altered the incidence of colon tumors produced by DMH and AOM in rats.